This invention pertains to a swing clamp usable with machine tools and other devices wherein a clamp arm may be moved from an inoperative position to an operative position overlying an object, such as a workpiece to be clamped, and with the clamp arm then being moved into clamping relation with the object.
The prior art includes Northern et al Pat. No. 3,173,673 showing a swing clamp wherein opposed pistons operate against a pair of pins at the lower end of a pivot shaft. This structure does not have sufficient strength to resist impact and loading forces encountered in normal as well as abnormal operating conditions of the swing clamp nor does it have two-directional capability of operation with interchangeable valve components.